On Saturday, November 22, 2014 4:01:08 PM UTC-6,
NVIS is generally defined as aiming the power straight up and the S
in NVIS stands for "Skywave". So if you want to be pendatic, you are
correct.

However, if you look at the links above, the real world DOES make
a distinction between NVIS and skywave.

I'll have to read through them, but myself, I consider any signal
which is reflected off the ionosphere back to the target receiver, as
being skywave, no matter if the angle is 90 or 10 degrees.
If it doesn't use the ionosphere, it's not skywave. Sometimes you can
have a mix of path modes. IE: being able to receive both the skywave,
but also the ground or space wave. In most cases like that, the NVIS
path will overwhelm the ground or space wave unless the two stations
are very close together.